Because between “I understand that this is not mutually exclusive” and “I can also implement my findings” are sometimes light years. Incompetence, organizational obstacles, personal vanities and measuring tails (very popular especially in companies with very few women in upper management), laziness & disinterest on the part of project management, so what the competition is doing is simply copied … the list is long, why so often the wrong thing is done, even though most of the people involved know that it is wrong. Your examples show that commercial success is NOT prevented if both exist in parallel.
The argument that you can cover all customers with Online-Only and thus potentially monetize more potential customers is a popular commonplace in presentations. That all sounds sensible, and sometimes this can be the case, but whether this is actually always the case and whether it isn’t better to differentiate from individual case to individual case … no one checks. Too laborious. Salary comes up every month and as long as the President is coherent enough for the board, everything is fine. And in the event that all of this doesn’t really work … volatile markets, high risk, consumer behavior that is difficult to assess, purchasing power development, phousy competition, blah blah blah … just typical corporate brain fuck that often enough doesn’t have much to do with reality.